The stereochemistry of enzyme catalyzed phosphoryl group transfer using a phosphoryl group of known chirality. The reaction of chemically-synthesized chiral D-glyceric acid 2- and 3-(18O) phosphorothioates with enzymes of the glycolytic pathway will continue to be studied. The molecule ATP gamma S gamma 18O (the gamma-phosphorothioate of ATP, chiral at the gamma-phosphoryl group by virtue of 18O) will be used to investigate the stereochemical course of pyruvate kinase, glycerol kinase, and hexokinase.